Human induced pluripotent stem (iPS) cells can display a naïve or primed state of pluripotency (Nichols and Smith, Cell Stem Cell (2009) Vol. 4(6), pp. 487-492). Primed human iPS cells express characteristics similar to those of post-implantation epiblast cells, and are committed for lineage specification and differentiation. By contrast, naïve human iPS cells express characteristics similar to those of embryonic stem (ES) cells of the inner cell mass of a pre-implantation embryo. In some respects, naïve iPS cells are more pluripotent than primed cells, as they are not committed for lineage specification. Various culture conditions can be used to maintain human iPS in a naïve state or in a primed state.